Foul Water and Mains Water

[willst0ne]

I have a mains water pipe running the length of a conversion I am doing. It is 6m away and 950mm deep. Will I be able to burry a foul water pipe running to a septic tank over the top of it? And, if so, are there any regs surrounding it? I've found some statements of 500mm between foul and mains water.
Thanks in advance

 

[noseall]

There is no reason or regulation why you cannot run a mains water pipe in the same trench as the foul waste pipe.

I fail to understand why you would want it buried beneath it though?

 

[willst0ne]

The mains pipe is being laid first as we are having to get it diverted. I will then be digging a new trench to lay the waste pipe at a later date. I just wanted to check there were no regs and then have problems later with where the main has been laid especially if I could do something about it now. Thanks for your info. W